1. Field of the Invention
The present invention relates to a separator structure for partitioning the interior of a chain case accommodating therein a chain-sprocket mechanism for rotating a crankshaft and camshafts in an interlocking fashion.
2. Description of the Related Art
An engine is known in which a part of oil used for lubricating a valve train while the engine is driven is constructed so as to flow down within a chain case accommodating therein a chain-sprocket mechanism provided on one end face of a cylinder block in a crankshaft direction for rotating a crankshaft and camshafts in an interlocking fashion.
Here, when a large volume of oil flowing down from a cylinder head to an oil pan is brought into contact with the chain-sprocket mechanism, as a matter of inconvenience, not only is rotational friction increased, but also the oil is diffused to thereby promote the misting of oil. Therefore, it is highly desirable that the oil flowing down from the cylinder head into the oil pan is prevented from being brought into contact with the chain-sprocket mechanism.
Japanese Patent Unexamined Publication No. Hei.8-218835 discloses an engine constructed from a viewpoint described above such that an oil passage is defined inside a chain case by a separator (partition wall) provided on the back of a stretched side portion of a chain.
However, application of the aforesaid related art becomes difficult if the chain line is not situated at a position suitable for provision of the separator. Moreover, if it is tried to secure a sufficient cross-sectional area for the oil passage between the back of the chain and the chain cover, it is inevitable that the engine is made larger in size.